Safety attachment for synchroscopes.



P. E. MEANS.

SAFETY ATTACHMENT FOR SYNCHROS COPES.

APPLICAHON HLED Aue.6. HHS.

1,230,003. Patented June 12, 1917.

2 SHEETS-SHEET 1.

P. E. MEANS.

SAFETY ATTACHMENT FOR SYNCHROSCOPES.

APPLICATION FILED Aue.6.1915.

1,230,003. Patented June 12, 1917.

2 SHEETS-SHEET} I I 5 L2 gwuemto a UNITED STATES PATENT OFFICE.

PLINY E. MEANS, OF TYRONE, NEW MEXICO.

- SAFETY ATTACHMENT FOR SYNGHROSCOPES.

To all whom it may concern:

Be it known that I, PLINY E. MEANS, a citizen of the United States, residing at Tyrone, in the county of Grant and State of New Mexico, have. invented certain new and useful Improvements in Safety Attachments for Synchroscopes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to new and useful improvements in synchroscopes.

The principal object of the invention is to provide a device which will prevent the cutting in or tying together of two sources of alternating electric current until the same are in proper synchronism.

Another object of the invention is to provide a device which will insure the two generators being in phase before they can be thrown into parallel.

A further object of the invention is to provide a device capable of being readily attached to the ordinary synchroscope without making any material change therein.

Still another object of the invention is to provide a'device which will prevent the flow of current into the line until the hand of the synchroscope is in such a position as to indicate that the two generators are in phase.

With the above and other objects in view, the invention consists in the novel combination and arrangement of parts which will be fully set forth in the following specification and accompanying drawings, in which:

Figure 1 is a face view of a synchroscope showing this improved device applied thereto.

Fig. 2 is a fragmentary vertical sectional view through Fig. 1.

Fig. 3 is a horizontal sectional view through Fig. 1.

Fig. 4 is a vertical sectional view of the modified form showing the attachment apdicates when its vertical position that Specification of Letters Patent. Patented June 12 191% Application filed August 6, 1915.

Serial No. 44,045.

the two generators are in phase. Carried by the shaft and rotatable therewith is a bridging contact 4, which has secured thereto the spring 5 by means of the rivets 6, which extend through slots in said spring and into the contact. This spring 5 bears against the inner side of the hand 3 so that the contact 4 is normally held spaced from the hand.

Hinged to one side of the casing 1 and extending transversely thereof is the bar 7, provided intermediate its end with the enlargement 8, having the opening 9 formed therein and this enlargement carries a suitable insulating material 10 on which the contacts 11 are mounted. These contacts are arranged to cooperate with the bridging contact 4 in completing the circuit when the hand is in its vertical position. Pivoted as at 12 to the end of the bar 7 opposite the one which is pivoted to the casing 1 is a rod 13, the opposite end of which is connected to the sliding core of the solenoid which will be more fully hereinafter described.

The solenoid is designated generally by the numeral 14 and comprises the coil 15 provided with the sliding core 16, one end of which is connected to the rod 13. A suitable casing 17 surrounds the core and the coil and is provided with an opening 18 through which the rod 13 is slidable. A coil spring 19 bears against the inner face of the casing 17 and against one end of the solenoid core 16 so as to normally hold the core within the coil. A thumb screw 20 is threaded into the end of the core 16 of the solenoid opposite the end to which the rod 13 is connected and bears against the end of the casing. This thumb screw is designed to adjust the movement of the core so as to control the movement of the arm 7.

It is to be understood that if so desired the contact 11 may be supported as illustrated in Fig. 5 on suitable springs 21, which may be rigidly attached to the face or to the rear' of the casing 1. It is of course to be understood that these springs or contacts are insulated from each other to avoid closing the circuit until the bridging contact 4 engages the same. It is further to be understood that the contact and bridging contact 4 may be placed on the rear of the casing 1 as indicated in Fig. 4 so as to carry the same to a point where it will be out of sight, and also allowing all con tacts to be made in the rear of the synchroscope. In connection with the operating lever it will be understood that the same may be connected in any desired manner to the casing or to any suitable support wh1ch will allow the same to operate in the manner set forth, in the above.

Upon referring to the wiring diagram, Fig. 6, it will be seen that the exciting current is carried over the bus bars A from the exciter and the cutting in of the A. C. generators is controlled by the main switches B and C. These switches being controlled by the solenoids 22 and 23 respectively, and one terminal of the solenoid 22 .is connected by means of the wire 2a to the contact 25 of the control switch designated by the numeral 26. The contact 27 of the control switch is connected to the wire 28, which leads to one of the contacts 11 of the synchroscope. This contact will be designated a. The opposite contact 11 of the synchroscope is designated by the character I) and is connected to the wire 29 which leads to the terminal of the solenoid 22 opposite the one to which the wire 24 is connected. The switch blades 30 and 31 are respectively pivoted to the contacts 32 and 33 of the control switch 26 and these contacts are respec tively connected by means of the wires 34 and 35 to two of the bus bars A as shown. A suitable shunt wire 36 is connected to the third bus bar A and the opposite terminal of the shunt wire is connected to the solenoid 15, the opposite terminal of which is connected to the wire 37 which in turn is in electrical connection with the wire 28. It is to be understood however that any suitable wiring diagram may be used without departing from the spirit and scope of the invention as it is realized that varying circumstances and conditions may require more than the specific wiring diagram set forth above. It is to be understood that such changes as may be required to meet the varying conditions may be made without in any way departing from the spirit and scope of the invention.

In the operation, it will be evident that one of the generators is already in operation and the current is passing over the bus bars A and a second generator is to be cut in and run parallel with the first mentioned generator, the control switch 26 is closed so the current passing over to the bus bars A will pass through the wire 35 into the contact 33, thence through the blade 31 into the contact 27 and back through the wire 28, through the wire 37 in the solenoid 15 and the current then passes through the wire 36 of the opposite bus bar A. It will also be noted that simultaneous with the closing of the switch 26 the contact a of the synchroscope 1 will be charged. It will also be noted that the contact 6 of the synchroscope will be charged as the said contact is connected with the second bus bar A by the means of the wire 29, solenoid 22, wire 24, contact 25, blade 30, contact 32 and wire 34. The synchroscope is connected 1n the ordinary way so that the hand 3 carried thereby will indicate whether or not the generator which is being run up is in phase. When the hand stands ertical it is understood that the generators are in phase 5 and the same are ready to be thrown into parallel by the manipulation of the main switch. The operation of the main switch is controlled by means of the solenoid 22 and this solenoid is energized when the g0 bridging contact t engages the contacts a b so that the current flows from one of the bus bars A into the wire 35, thence through the control switch 26 into the wire 28, thence to the contact a, through the con- 35 tact 4: and into the contact I), from whence the current passes into the wire 29 and solenoid 22 through the wire 2& and the control switch 26 into the wire 34, thus energizing the solenoid and causing the main switch to close throwing in the second generator. The solenoid 15 which is shunted causing the first and second bus bar of the bars A is also energized so as to pull the arm 7 outwardly and cause the contacts 11 previously referred to in the wiring diagram as ab to move into such position as to be engaged by the bridging contact 4. Owing to the fact that the contacts 11 are eccentrically mounted with relation to the shaft 2, it will be seen that current cannot pass into the main switch solenoid 22 unless the hand stands in a vertical position.

lVhile in the foregoing there has been shown and described the preferred embodiment of this invention, it is to be understood that such changes may be made in the combination and arrangement of parts as will fall within the spirit and scope of the appended claims.

What is claimed is 1. In a synchroscope, a dial, a hand movable over the face of the dial, a bridging contact carried by said hand, an arm pivoted to the side of the synchroscope, a ring centrally of the arm, a pair of contacts arranged at diametrically opposite points on said ring and in such a position that when the hand indicates synchronism the bridg ing contact will bridge the diametrically ar- 1 ranged contacts and a solenoid for moving the diametrically arranged contacts into engagement with the bridging contact when the device is set in operation.

2. The combination with a synchroscope having a movable bridging contact and fixed contacts coiiperating therewith normally out of the path of the bridging contact, of magnetic means for moving the latter contacts into said path, a source of eurrent and a controlling switch for energizing said magnetic means, a main switch and connections establishing a circuit comprising the source, the fixed contacts, the main switch and the controlling switch.

3. A synchroscope comprising a casing, a dial on said casing, an arm pivoted to the side of the casing and extending across the face of the dial, a ring centrally of the arm, a pair of diametrically opposed contacts on said ring, a link pivoted to the free end of the arm, a solenoid operating on said link to swing the arm on its pivot, said solenoid tending to move the arm away from the dial, a hand movable over the face of the- PLINY E. MEANS.

lVitnesses SALLIE Gr. POLLOOK, E. MAY BOYCE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

